Deformed Richardson-Gaudin model

Artikel i vetenskaplig tidskrift, 2014

The Richardson-Gaudin model describes strong pairing correlations of fermions confined to a
finite chain. The integrability of the Hamiltonian allows the algebraic construction of its eigenstates. In this
work we show that the quantum group theory provides a possibility to deform the Hamiltonian preserving
integrability. More precisely, we use the so-called Jordanian r-matrix to deform the Hamiltonian of the
Richardson-Gaudin model. In order to preserve its integrability, we need to insert a special nilpotent term
into the auxiliary L-operator which generates integrals of motion of the system. Moreover, the quantum
inverse scattering method enables us to construct the exact eigenstates of the deformed Hamiltonian. These
states have a highly complex entanglement structure which require further investigation.